Process of making artificial stone



(No Model.)

0. W. STEVENS. PROCESS or MAKING ARTIFICIAL STONE.

Patented June 1, 1897.

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CHARLES XV. STEVENS, OF LANSING, MICHIGAN.

PROCESS OF MAKING ARTIFICIAL STONE.

SPECIFICATION formingpart of Letters Patent No. 583,515,

Application filed September 7, 1895, Serial No. 561,771.

dated June 1, 1897.

(N0 specimens.)

T0 at whom, it 717.41.7 concern..-

Be it known that I, CHARLES W. STEVENS, a citizen of the United States,residing at Lansing, county of Ingham, State of Michigan, have inventeda certain new and useful Improvement in Processes of Making ArtificialStone; and I declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it pertains to make and use the same, reference being hadto the accompanying drawings, which form a part of this specification.

This invention relates to the manufacture of artificial stone, and hasforits object an improved process of manufacturing either plain orornamented artificial stone.

In carrying out the process the stone may be made either in the placewhere it is to be permanently used or in a factory, whence the finishedblocks or pieces of stone are removed to their place of ultimate use.The process of making the stone is the same, but the appliances woulddiffer somewhat under the different conditions.

The process consists in making a mold in sand or a mold partly of sandand partly of other material, facing the mold with the material of whichthe artificial stone is made, filling in behind the facing thus madewith sand, and then saturating the mass of sand and material with water.

The process is applicable to any form or style of stone, but isparticularly applicable to what may be considered hollow stone. I havefound it entirely practicable to make stone in the form or shape ofhollow building-tile with strengthening cross-webs and stone forcornice-work or ornametal coursework in which the stone was merely athin shell deeply concaved. I have also found it practicable for makingstone with a facing of fine and expensive material, such as required theuse of colored sands or mottled work and which are backed up withcoarser and cheaper material. The-appliances required are a box, thatmay be compared to a molders flask, and a quantity of fine sand andgenerally a pattern of the face or faces of the finished stone and aparting-board or set of partingboards. These parting-boards should bethin and are preferably of sheet metal and of course are shaped and cutto accord with the pattern. A skilful workman can form the model in manycases without a pattern by sweeping it and can frequently dispense withparting-boards, but these appliances aid greatly in making intricatework.

In the drawings, Figure 1 showsin perspective a box or flask. Fig. 2indicates a section through a flask with stone and sand in position.Fig. 3 shows in perspective a pattern in two pieces and a parting-board.Fig. 4 shows in sectional elevation a cornice-stone set in the brickworkof a wall.

A indicates the flask or box employed in forming a detached piece ofstone-that is, one not made in the place it is to remain permanently.

B 0 indicate a two-part pat-tern, this form of pattern being shown asillustrative merely and'the form of stone shown being adapted tocornice-work.

D indicates a partingboard.

In the case illustrated one side of the flask A is utilized as a part ofthe mold and the plane face a is made against the side of the flask. Themolded part between the ends of the caret b is molded against sand. Thebottom piecee is also molded against or on sand.

A layer of molding-sand, moistened enough to hold its shape, is placedin the flask and the pattern placed in position and sand crowded intoall the irregular parts, as under the irregular parts indicated at b.The pattern is then removed, leaving a matrix of the pattern or of apart of it. With a pattern of the form shown in the drawings this matrixwould extend from the junction of the face a and the face I) to theangle between the face f and the face 6. Over this matrix is now spreadthe dry stone compound in fine powder, the cement being dry groundPortland or similar cement and the sand being ground stone of theselected variety, its fineness depending on the character of the work tobe produced.

The coating of dry powdered-stone material is spread over level parts tothe depth of the proposed stone, or very fine expensive ma terial may bespread shallowly and backed up with coarser material. Where the patternrises vertically, a parting-board is used and this is inserted, as alongthe line (1 d", and

the stone material filled in on one side, while sand (Without anycement) is carried up on the other until all the horizontal parts havebeen covered with sand. he pattern for the return fold g is placed, sandfilled around it to the level of the upper face, the pattern removed,and stone material filled in and leveled oft. Two or three inches moreof sand is filled in, a loose board 71. laid over this, and water pouredinto the box until the contents are saturated. Provision should be madeto have the Water drain away slowly, but it should not run through sofast as to Wash any of the material out of place.

An expert Workman can place material and sand in place oftentimesWithout the use of the partingb'oard, and the board 71 is only necessaryto prevent displacement of the sand and material.

After the cement has set it is removed from the flask and themolding-sand cleaned ofi and the stone allowed to cure.

I have found that the most accurate following of fine lines of patternsare attained when the stone material is fine and dry, as with thematerial in this dry condition even the fine veins of leaves can becopied accurately. However, where it is not desired to make sharp anglesand delicate lines a moist material can be used, and if moist enough toadhere slightly the use of parting-boards can be entirely omitted.

hat I claim is 1. The process of forming artificial stone consisting ofplacing a layer of stone compound between layers of sand and saturatingthe mass with water, substantially as described.

2. The process of making artificial stone, consisting of forming in sanda partial mold of one or more faces of such stone, filling into thepartial mold thus formed a lining of stone compound,coveri n g theexposed faces of stone com pound with sand and saturating the mass WithWater, substantially as described.

' In testimony whereof I sign this specification in the presence of twowitnesses.

, CHARLES W. STEVENS.

\Vitncsses:

CHARLES F. BURTON, VIRGINIA M. CLoUen.

